Daytime Running Light Relay Circuit

LIGHTING (EXT): LIGHTING SYSTEM: Daytime Running Light Relay Circuit

Daytime Running Light Relay Circuit

DESCRIPTION

The main body ECU (driver side junction block assembly) controls the daytime running lights (dimmed high beam headlights).
HINT:
- The power distributor (engine room junction block assembly) has a headlight control function. This function dims the high beam headlights in accordance with operation signals from the main body ECU (driver side junction block assembly) while the daytime running light system is operating.
- The power distributor (engine room junction block assembly) dims the high beam headlights using a duty control.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Main Body / Active Test.
(e) Check that the relay operates.

Main Body





OK:
Relay operates. (Daytime running lights illuminate.)

NG -- CHECK HEADLIGHT
OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE
2. CHECK HEADLIGHT
(a) Check the operation of the high beam headlights.
OK:
High beam headlights operate normally.

NG -- GO TO PROBLEM SYMPTOMS TABLE
OK -- Continue to next step.

3. INSPECT POWER DISTRIBUTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY)




(a) Remove the engine room junction block assembly from the engine room relay block Components.
(b) Connect a positive (+) lead from the battery to terminal 1A-1.
(c) Connect a negative (-) lead from the battery to terminal 1F-16.
(d) Check for pulses according to the value(s) in the table below.
Standard:





Text in Illustration





NG -- REPLACE POWER DISTRIBUTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY)
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - MAIN BODY ECU)




(a) Disconnect the 1F power distributor (engine room junction block assembly) connector.
(b) Disconnect the D51 main body ECU (driver side junction block assembly) connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)